When operating construction machines, attachment devices are often used that are mounted to the outside of the machines. In other words, the attachment devices are applied to the construction machines in such a manner that they are accessible from outside the construction machine. In this case, construction machines refer particularly to road construction machinery, such as road pavers, road milling machines, stabilizers, recyclers, and road rollers or other soil compacting machines, e.g., landfill compactors. For example, sensors that serve to increase operational safety and/or to improve precision in control are considered to be attachment devices. For example, cameras are used as attachment devices particularly with road pavers and road milling machines in order to enable the driver to have optimum visibility of the paving or milling process.
These attachment devices are typically relatively expensive and/or prone to vandalism. Therefore, it is often necessary to remove them from the construction machine at the end of a workday and to reattach them once again the next workday so that the attachment devices cannot be damaged overnight or even stolen. Widespread use of these attachment devices is also frequently not required, so it is not always necessary to equip every machine with respective attachment devices. Thus, it is viewed as an advantage if one and the same attachment device can also be used on different machines on an alternating basis.
Until now, the attachments devices, particularly cameras, have been mounted, for example, by means of screw connections. These enable reliable mounting of the attachment device. However, it takes a relatively long time to remove the attachment device at the end of the workday, which creates the hazard that the operator just leaves the attachment device on the construction machine, which leads to the above-described risks. Moreover, the attachment devices can only be attached where there are corresponding screw holes and/or sockets on the construction machine for accommodating the attachment device.
To simplify and speed up the installation or removal of the camera, attachment devices having magnetic brackets are used. They have the added benefit that they do not require a socket on the construction machine and therefore can be mounted anywhere depending on where they are intended to be used. However, the disadvantage of the known magnetic mountings is that, while they can be quickly mounted anywhere on the construction machine, it is time-consuming to adjust the attachment device to the desired orientation. In particular, this relates to the use of cameras as attachment devices, which are normally to be mounted on the construction machine with a defined angle of view. The adjustment of the camera constitutes a relatively time-consuming task. By contrast, the orientation of the attachment device is predetermined in the case of screw connections by the position of the screws holes. This type of constant alignment is lacking with magnetic mountings, which can be used anywhere on the construction machine. The correct orientation of the attachment device must be freely adjusted by hand. Thus, effort that was saved as a result of the quick installation is in turn at least partially wasted on the time-consuming adjustment or alignment. This is particularly the case if an exact alignment of the attachment device, particularly the camera, is important, for example, if the camera is used as a sensor device to simplify the loading of milled material (as disclosed in US 2013/0080000 A1), or if other image processing steps occur.